For the second time someone has claimed my son on there taxes it happened for the 2011 taxes and now the 2012 . I have a good idea on who is doing it but i have no proof so i was told i can not start a fraud case. i know its not my sons mother because i have seen her taxes for last year and this year we have a order stating i am to claim him for 2012 taxes. i will be attempting to change his SSN but i also want the person responsible to be properly dealt with. last year the IRS told me they would send letters to each party that claimed the same exemption around Oct but they never sent the letter what should i do?